Questions tagged [experimental-technique]
filling in the unspecified details of elegant-sounding descriptions of experimental methods.
412
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In four probe experiment why the graph looks like in low temperature
I found a graph between the log of resistivity vs inverse of temperature like this
So in region 2, why is the graph going down?
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How does MEMS low insertion loss fiber optic switch work? [closed]
I'm currently looking for a low insertion loss fiber optic switch to be able to change the light source of a spectrometer. Since this will be used in harsh conditions, I was hoping to find one with no ...
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1
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Why were multiple layers of absorbers and scintillators used in the CMS HCAL?
Why were multiple layers of absorbers and scintillators used in the CMS HCAL? Couldn't they have used just one absorber and one scintillator layer? Why was the choice made to have multiple layers?
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Are there references of influences on physical processes in experiments?
Suppose I have some physical process to use in some experiment. For instance, let's consider just looking at an object to measure its position.
The basic modelization for this is to consider geometric ...
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Condensation on the side of a cloud chamber
I'm trying to build a cloud chamber using a peltier thermoelectric cooler. So far, I've managed to detect some particles, but their trails are very weak (I've used a high voltage generator, about 4kV, ...
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Why is my measured value of magnetic flux in the experiment larger than the theoretical value calculated?
I recently did an experiment to investigate the emf induced in a coil by letting a magnet fall through a coil. The voltage was measured by a voltage sensor, and then plotted against time on a Capstone ...
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Measuring the acceleration due to gravity using an experiment [closed]
A student measures the acceleration due to gravity, g, using the
apparatus shown in the figure below. A plastic card of known length is
released from rest at a height of $0.50$ metres above a light ...
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2
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Prevent Foucault's Pendulum from an Ellipticity
I am using a 15kg dumbbell as the bob of a Foucault's pendulum attached to a string of 4 meters. However, using the common method of burning a wire to set the bob in motion, it will begin to oscillate ...
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How do we know the location of entangled particles after leaving the source so that we can set up our measurement devices?
Studying the Bell Inequality and was wondering how exactly experiments like Bell's are conducted. I understand the premise of the experiment to be that an entangled pair of photons or other quantum ...
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What is the difference between conventional thermocouples and differential thermocouples? And how to calibrate the differential thermocouples?
I am now setting up thermal transport measurement device for small diameter sample. I found a model, metioned in this paper(https://doi.org/10.1063/1.1347980), callled parallel thermal conductance ...
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Cryogenic and vacuum safe cable labeling or tagging
Not the most in depth of physics questions, yet this feels like the right community for trying to crowd-source this type of expertise.
Essentially it is a question for those of you experienced with ...
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Experimentally Tracking Fluid Flow
I've been facing this issue and I will be very grateful if anyone could offer insights!
I have a stream of water that starts out from a nozzle flowing down vertically. The stream of water hits a ...
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1
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65
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How can an experimental physicist create a free electron gas in air? [closed]
Suppose an experimental physicist has to create a free electron gas in a test chamber filled with air or any gas. They can do this with arcing, photoelectric effect, or others. What would be the best ...
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Experiment preparation - Box to reduce background photons noise
I am planning to perform experiment with a photomultiplier tube (PMT) in my lab. The system is not large, with a length scale of about 10 cm. I am looking to reduce the background photons noise as ...
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How to measure spectral irradiance vs wavelength for sunlight?
I am currently working on a project where I need to measure the spectral irradiance over a submerged solar panel at different depths of water. But I do not really know what can be used to measure it. ...
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Experimentally Measuring the Velocity of Water coming out of an Orifice
I plan on doing an investigation into Torricelli's Law, where I will be looking at one of the following:
How the cross-sectional area of an orifice affects the velocity of water coming out of it (...
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What is an event-ready scheme (at-a-glance) in the context of Bell-type tests?
The abstract of Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres says
We use an event-ready scheme that enables the generation of robust entanglement between ...
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Distinguishing between circularly polarised light and non-polarised light
When a non-polarised light passes through a polariser, the components parallel to the transmission axis will pass through, and we can "observe" that it is linearly polarised by taking ...
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Holding Electric Potential Constant Between Two Plates
Let's say I had the following laboratory set-up:
Two conductive plates with an electrical potential $\phi$ between them, and a fluctuating potential $\phi$ (created by some arrangement of fluctuating ...
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2
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Experimental measurement of the coefficient of static friction
In the experiment section of a regional physics competition, we were asked to experimentally determine the $\mu_s$ of an acrylic block against three kinds of surfaces. One of the sub-questions asked ...
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Automation and remote controlling
I am very new in the field of experimental physics. I want to pursue research in the condensed matter physics. I have observed that most of the instruments such as lock-in amplifier, digital current ...
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1
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Are all Astronomers also technically physicists? [closed]
There is a website many schools will use to show their students job descriptions to give them inspiration and know what they wish to be when they grow up, show them some options, you know?
Well, I was ...
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What are internal and external estimates of error?
I have n measurements for a quantity, and I need to calculate the internal and external estimates of error. I know what standard error is and how it is calculated, but have no clue regarding internal ...
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Measure small mass change on heavy item [closed]
I need to measure the change in mass on a large number of components we are developing with a size of a large orange and weighing between 0.3 and 1 kg to an accuracy of sub 10x10-6 kg. The mass will ...
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Papers of real experiments measuring momentum of individual particles?
I am trying to understand the different methods that have been used to measure the momentum of individual particles. I have been able to find a few methods (with corresponding papers describing the ...
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Falling yoyo experiment
I was playing with a yoyo and a spring dynamometer and realized the tension during the fall is not constant but clearly has a small oscillatory component. This experimental result contradicts the ...
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Experimental design and precision for calculating moment of inertia
Here is the experiment: A hanging mass is placed on one end of a three-step pulley. The pulley rotates a rod with masses, $m_1$ and $m_2$, on each end.
Now, we know the moment of inertia of the two ...
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Rate Upper Limit Inference With New Background
I am trying to set an upper limit on a process in an experiment. Over a given time period I observe $N_1$ events, which are all likely to be from a background. The background events are a Poisson ...
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1
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How can a neutral atom, e.g., a rubidium atom, be accelerated to a high speed? [closed]
I have this question because I am studying quantum friction for my PhD project.
Quantum friction could refer to the frictional force induced by the electromagnetic field fluctuations on a neutral ...
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2
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How is time measured in particle experiments?
I was reading about the half life measurements and was curious to understand the experimental setups that allows so minute measurements to be captured. Specifically looking into half life of Higgs ...
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Experiments check out theories but who or what checks out the experiments? [closed]
There is a classic saying which goes more or less like this:
If your theory is not verified by the experiment then it is wrong!
Specifically for the field of particle physics, lately experiments ...
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Measuring radius vs diameter for a circular ring?
Consider an experiment where I have to measure the radius of a circular ring diffraction (or interference) pattern (think Newton's rings).
It is advised to measure the diameter and then divide it by ...
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236
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Single slit diffraction with a slit width much larger than the wavelength
It is known that for a diffraction pattern to be strong, the wavelength of incoming laser light should be comparable to the slit size.
The reason being if the slit is very narrow it effectly is a ...
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2
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How can we conduct experiments to verify formulas without special equipment? How was it done in the past?
If we wanted to verify experimentally/empirically as laymen without special instruments a formula such as $s=16t^2$ which is used to approximate the distance s, in feet, that an object falls freely ...
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Understanding the 'Truncated DFT' for Moiré Phase Analysis
I am researching the use of a Moiré sampling algorithm in order to determine the two-dimensional displacement field of an object. In the paper of Wang and Ri (2022), the algorithm is described. ...
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1
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What is a proper resolution, and how many times of measurement needed for a credible experiments? [closed]
This question aims to understand a basic intuitive understanding and proper doing in practical situations for designing experiments.
Resolution
Suppose there is an object large as a hand. What is ...
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Charge separation by friction: Experimental problem
In introductory electrostatics one often sees an experiment where the instructor rubs a rod (for example a PVC or a glass rod) with a cloth (for example made of wool, cotton or silk). And then strips ...
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Can laser diode characteristics comparison be based on laser of one length?
As we know, e.g. from this website, to know the laser Transparency Threshold Current and Internal Quantum Efficiency, we need the LI curves from lasers of various widths.
However sometimes it is ...
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What are the sealing adhesives for high vacuum system?
Recently, I have a project that needs to use a high vacuum system. During the construction process, I encountered a problem: I need to stick mica or glass to the window of the copper wall (one side is ...
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One-way speed of light confirmation, not measurement [duplicate]
So there's quite a few posts on here about the now infamous YT video about how the speed of light can only be measured as a round trip. I think I understand the issues with the proposed experiments I'...
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1
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What are some physical or mathematical conecepts/techniques that can be used to "easily" do numerical experiments/analyses in physics? [closed]
Basically I'm asking for concepts/techniques (don't know if it's the right word) that can be used/applied "easily" to eg. a physical system. It might be used to identify a behavior or a ...
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2
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How can we detect neutrons?
If I am asked to design a simple experiment to detect neutrons, how can I do that?
The problem is, neutron is a neutral particle. So, application of electric and magnetic fields won't help. Can I ...
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What is required for a minimum viable Bell test experiment at home?
My objective is to create a tabletop Bell test experimental setup generating data of suitable quality for undergraduate education or satisfaction of personal curiosity; remaining free from loopholes ...
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How to get FFT spectrum of acceleration measurement?
I use an Accelerometer to measure acceleration (normalized via the gravitational acceleration $g\simeq9.81\,m/s^2$, so if one axis is orthogonal to the ground it returns the value 1). I already ...
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What is the maximum virtual depth achievable in a printed hologram?
I remember a few years ago printed holograms were quite fashionable. Even though they still had different colors from reality, I found them quite impressing.
I wonder if there has been any progress in ...
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One-way speed of light experiment, no clocks or mirrors (with simulation)
As can be seen in the many creative questions here, it is hotly disputed whether you can measure the speed of light in only one direction to the point where a infamous postulate was made that the ...
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Uncertainty of angle with known uncertainty of cosine of angle
Quick question, how do I proceed if I managed to get (from some kind of a measurement) the value of $\cos(\phi)$ and its error $\sigma_{\cos\phi}$ and I'd like to find $\phi \pm \sigma_{\phi}$?
Would ...
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How do you stabilize the temperatures in your sensitive laboratory experiments?
I work in an AMO Lab, and I have been tasked with creating an experiment enclosure that will keep the air (and instruments) stable within about 50 mili-Kelvin with a set point of about 20C-21C. Our ...
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How to find thermal diffusivity
This is a question about nondimensionalization in the heat equation
$$\rho c \frac{\partial u}{\partial t}= \kappa \frac{\partial^2 u}{\partial x^2}~? $$
How could one devise a nondestructive ...
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Which one is more precise: Phase locked loop or log the waveform then do sliding FFT?
I have an experimental confusion. I am using an interferometer to monitor the movement of a translation stage by monitoring the intensity of the coaxis interference pattern of the He-Ne laser.
...
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